Medussa is a password cracking application that supports distributed processing. One node acts as the Medussa server and the rest of the nodes are running the client application. The server node, in addition to running decryption, also distributes the workload among all participating nodes. Below is brief installation and configuration manual for running Medussa under Linux.

Downloading Software

You can download Medussa source code from the developer’s site: http://www.bastard.net/~kos/medussa/

Save the medussa-0.8.tar.gz to /opt/medussa

cd /opt/medussa
gzip -d medussa-0.8.tar.gz
tar xvf medussa-0.8.tar.gz
cd /opt/medussa/medussa-0.8

Installing Server

To compile Medussa you will need the current version of gcc compiler. From /opt/medussa/medussa-0.8 do the following:

./configure
./make
./make install

Configuring Server

In /opt/medussa/medussa-0.8 create a hidden file called .medussarc. The file should contain the following:

#
# Basics
#
verbose 1
adminpassword your_pass
motd Medussa

Set permissions on .medussarc to 700.

Create a file /etc/init.d/medussa with the following contents:

#!/bin/bash
ps -ef | egrep "medussa|tentacle" | egrep -v egrep | awk '{print $2}' | while read PID
do
        kill -9 $PID
done
cd /opt/medussa/medussa-0.8/
/usr/local/bin/medussa -d -f .medussarc
/usr/local/bin/tentacle -v0 &

Medussa will only read the .medussarc file from the current working directory, so it’s important to cd to where this file is located rather than provide the full path to the file.

Set permissions:

chmod 755 /etc/init.d/medussa

Run /etc/init.d/medussa This will start Medussa server and a single client thread.

Installing Client

On each client node run the following script to download the source tarball from the server node, untar, compile, install, add startup scripts, and run. Substitute “head_node” and “root_pass” with the name of your Medussa server and the root password on that server.

#!/bin/bash

MSERVER="head_node"
FTPUSER="root"
FTPPASS="root_pass"
HOMEDIR="/opt/medussa"
TARBALL="medussa-0.8.tar"

if [ ! -d $HOMEDIR ]
then
	mkdir $HOMEDIR
	chmod 700 $HOMEDIR
else
	echo "Directory $HOMEDIR already exists. Exiting..."
	exit 1
fi

ftp -in $MSERVER < /etc/init.d/tentacle
chmod 755 /etc/init.d/tentacle

/etc/init.d/tentacle

Example cracking session

On the Medussa server type mecon to access the Medussa console and enter commands as shown to crack a single Unix password hash.

[root@medussa]# mecon
mecon> o
Implementation 0.8 [i686-pc-linux-gnu], ready and willing
mecon@localhost>admin your_pass
mecon@localhost>add hash username1 unixcrypt vvme8ohnOyMOI
mecon@localhost>add schedule username1 bruteforce poss=abcdefghijklmnopqrstuvwxyz1234567890,maxlen=7
mecon@localhost>show nodes
node                   cps       start time       total time   current slice
medussa2          R 70000    2006/05/10 13:52  0:00:00:01   210000:1210000
medussa3          R 70000    2006/05/10 13:52  0:00:00:01   1210000:2210000
medussa4          R 70000    2006/05/10 13:52  0:00:00:01   2700000:3700000
medussa5          R 70000    2006/05/10 13:52  0:00:00:01   3770000:4770000
medussa6          R 70000    2006/05/10 13:52  0:00:00:01   4770000:5770000
mecon@localhost>stat
eta: 0:13:49:17
percent: 0.055
totalcps: 1619045